We have shown that the presence of one particular lys-tRNA species can be correlated with the ability of a cell to divide. We are proposing that this tRNA has a specific role in the process of cell division. This lys-tRNA is very similar in its properties to one of the major lys-tRNAs, lys-tRNA2. We feel that lys-tRNA arises by one or several base modifications and experiments are underway to isolate these tRNAs and analyze for modified base content. The role that this tRNA might have in cell division is unknown, but we are currently testing the hypothesis that this tRNA may be specifically required for the synthesis of histones.